Passenger seat

Abstract: The seat pan (46) of an aircraft passenger sleeper seat is mounted on a pivot axle (48) for movement between a normal substantially horizontal position and a tilted position in which its front edge is lower than its rear edge. The seat back comprises a first portion (40) which is mounted for angular movement between a substantially upright position and a reclined position, and a second portion (42) mounted on a pivot axle (48) for movement between an erect position in which it is substantially parallel to the first portion (40) and a reclined position in which its upper edge is lower than when in its erect position. When the seat pan (46) is tilted and the second portion (42) of the seat back is reclined, their upper surfaces form a substantially plane support surface for a sleeping passenger.

Description: This invention relates to a vehicle seat of the type comprising a base frame, a seat back mounted on the base frame for angular movement between a substantially upright position and a reclined position, a seat pan having an upper surface, and mounting means supporting the seat pan on the base frame so as to permit change of the orientation of an upper surface of the seat pan between a substantially horizontal position and a tilted position in which its front edge is lower than its rear edge. A seat of this type is disclosed in US-A-5 058 954. The invention is particularly, but not exclusively applicable to a seat of the type which also has a legrest which can be raised. Such seats are commonly known as sleeper seats and are used extensively as aircraft passenger seats. US-A-3 865 432 discloses a reclining chair having a backrest reclinably mounted on a seat pan and a headrest mounted on the back rest for angular movement relative thereto. The chair also has a legrest. Many airlines use a pitch between successive rows of sleeper seats of about 62 inches (1575 mm). Consequently, it is not feasible to lower the seat back and raise the legrest of a sleeper seat sufficiently to form a continuous horizontal surface with the seat pan. With known sleeper seats, the maximum extent to which the seat back can be tilted is substantially above the horizontal. Similarly, the maximum extent to which the legrest can be raised is substantially below the horizontal. In this position, the seat back, seat pan and legrest form a zigzag surface which is fairly comfortable for people who sleep on their backs but is less comfortable for people who prefer to sleep on their sides. It is an object of the invention to provide a sleeper seat in which this disadvantage is reduced. According to the invention, the seat back of a vehicle seat of the type described above comprises a first portion which is mounted for angular movement between said substantially upright position and said reclined position, and a second portion having an outer surface supported on mounting means which permit change of its orientation between an erect position in which it is substantially parallel to the first portion and a reclined position in which its lower edge is substantially coplanar with the rear edge of the seat pan when said seat pan is in its tilted position. Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a sleeper seat in accordance with a first embodiment of the invention, with its legrest raised and its seat back inclined; Figure 2 is a perspective view of the embodiment shown in Figure 1 with the central portion of its seat back further reclined; Figures 3 and 4 are perspective views, similar to Figures 1 and 2, of a second embodiment of the invention; Figure 5 is a perspective view, similar to Figure 1, of a third embodiment of the invention; Figure 6 is a longitudinal cross-sectional view of the embodiment shown in Figure 5, with the legrest omitted; Figures 7 and 8 are views similar to Figures 5 and 6, of a fourth embodiment of the invention; Figure 9 is a perspective view of a tourist class seat in accordance with the invention with its seat back reclined in a conventional manner; Figure 10 is a side view of the seat back of the seat shown in Figure 9; Figure 11 is a perspective view of the seat shown in Figure 9 but with its seat back further inclined in accordance with the invention; Figure 12 is a side view of the seat back shown in Figure 11; Figure 13 is a perspective view of an alternative form of seat back in accordance with the invention in a normal reclined position; Figure 14 is a perspective view of the seat back shown in Figure 13 in a position in which it has been further reclined in accordance with the invention; Figure 15 is a schematic side view of two aircraft seats, one behind the other, both having seat pans of the type illustrated in Figure 8 and seat backs of the type illustrated in Figures 13 and 14, with the rearmost seat in its upper position; Figure 16 is a schematic view, similar to Figure 15 but with the rearmost seat in a normal reclined position; Figure 17 is a schematic view, similar to Figures 15 and 16 but with the rearmost seat in a fully reclined position; Figure 18 is a schematic view of a seat in accordance with an embodiment of the invention, employing adjustment by displacement of fluid, with its seat back reclined; Figure 19 is a schematic view of a seat in accordance with another embodiment of the invention, employing adjustment by displacement of fluid, with its seat back reclined; Figure 20 is a schematic sectional view of part of the seat pan of the seat shown in Figure 19, with its top surface tilted; and Figure 21 is a schematic sectional view of part of the seat pan of the seat shown in Figure 19, with its top surface horizontal. Figures 1 and 2 shows a sleeper seat in accordance with the invention. The seat comprises a base frame 10, whereby it may be secured in place in an aircraft. Armrests 12 and 14, and a seat pan 22 are all rigidly secured to the frame 10. A legrest 20 is secured to the front edge of the seat pan 22 so as to be movable between a stowed position (not shown) under the seat pan 22, and a deployed position, as shown in Figures 1 and 2. This seat also has a seat back consisting of a U-shaped outer part 24 and a separate central part 26 disposed between the limbs of the U-shape. The outer part 24 is pivotally attached by the ends of its limbs to the frame 10 for angular movement between an upright position (not shown) and a reclined position, similar to the normal reclined position of known seats, as shown in Figure 1. The central part 26 of the seat back is pivotally mounted for angular movement about a transverse axis near its bottom edge relative to the outer part 24 of the seat back between the position shown in Figure 1, in which it is generally coplanar with the outer part, and a lowered position as shown in Figure 2, in which it is more nearly coplanar with the seat pan 22. When in use in this position, the head of an occupant rests on the central zone 28 of the outer part 24 of the seat back, while the occupant's shoulder rests on the central part 26. The zone 28 thus serves as a pillow. With this type of seat the thickness of the outer part 24 of the seat back provides the necessary structural strength. The central part 26 is thinner so that its bottom surface does not project below that of the outer part 24 when in the lowered position shown in Figure 2 and thus does not interfere with the leg room of a person seated behind the seat illustrated. In some circumstances, the height of the zone 28 above the central part 26 (when the latter is in the position shown in Figure 2) may be too great for the zone 28 to be comfortable as a pillow, particularly if it includes a padded headrest for use when the seat back is in its upright position. Referring to Figures 3 and 4, the outer part 30 of the seat back may include a central recess 32 in which a headrest 34 is slidably mounted. When the central part 26 of the seat back is pivoted down, as shown in Figure 4, the headrest 34 slides away from the seat pan 22. A conventional pillow (not shown) can then be placed in the recess 32. Figures 5 to 8 illustrate a further embodiment of the invention having a base frame 10 and armrests 12 and 14 similar to those previously mentioned. The seat has a seat back with an outer part 40 similar to the outer part 24 of the seat back shown in Figures 1 and 2. However, the inner part 42 of the seat back is pivotally mounted for angular movement about a transverse horizontal axle 44 located approximately half way between the upper and lower edges of the central part 42. The seat also has a seat pan 46 which is pivotally mounted on a horizontal transverse axle 48 located about halfway between the front edge and the rear edge of the seat pan 46. A legrest 50 is mounted on the front edge of the seat pan 46 in a similar manner to the legrest 20 of the previous embodiments. When the seat is to be used either in its upright or normal recline position, the seat pan 46 is pivoted to a substantially horizontal position and the central portion 42 of the seat back pivoted so as to lie parallel to the outer portion thereof, as shown in Figures 5 and 6. When the occupant of the seat wishes to sleep, the central part 42 of the seat back is pivoted so as to raise its bottom edge and the seat pan 46 is pivoted so as to raise its rear edge as illustrated in Figures 7 and 8, so that central part 42 of the seat back, the seat pan 46 and the legrest 50 all lie in the same inclined plane. As can be seen in Figures 6 and 8, the outer part 40 includes a central opening 52 behind the lower part of the pivoting central portion 42 which allows the outer part 40 of the seat back to be pivoted considerably lower than would otherwise be the case before it encroaches on the foot space of a sleeping occupant of a seat behind the seat illustrated. In all of the embodiments described above, the seat back, the seat pan and the legrest can be oriented so that they all lie in the same inclined plane. The invention also includes seats of the above type in which there is always a non-zero angle between the seat pan 22 and the seat back 26 and/or between the seat pan 22 and the legrest 20. Figures 9 and 10 show a tourist class seat in accordance with the invention. The seat comprises a seat pan 60 which is secured to a conventional support frame (not shown) whereby adjacent seats may be mounted in a row. The seat has a pair of armrests 62 and 64, and a seat back subframe 66 which is pivotally mounted for angular movement relative to the seat pan 60 about an axis adjacent to the rear edge of the seat pan 60. As can be seen from Figure 10, the subframe 66 has a seat-back cushion 68 pivotally mounted thereon for angular movement about a transverse axis 70 located approximately halfway between its upper and lower edges (in a similar manner to the seat back of the seat shown in Figures 5 to 8). The subframe 66 also carries a headrest 72 above the top edge of the seat back cushion 68. As can be seen from Figures 11 and 12, the back cushion 68 can be pivoted to a position in which it is further reclined relative to the subframe 66. Figures 13 and 14 show an alternative seat back which can be used with a seat having a seat pan which can pivot about an axis adjacent to its rear edge so as to lower its front edge. This alternative seat back has a subframe 76 which extends only halfway up the seat back and which has an axle 78 at its upper end on which a seat cushion 80 is pivotally mounted. Figures 15 to 17 show a pair of seats, one behind the other, each having a seat back as illustrated in Figures 13 and 14. In Figure 15, the rearward seat is shown with its seat pan 82 in a horizontal position and its seat back 84 in an upright position. The seat immediately in front is shown in solid lines with its seat pan 86 horizontal and its seat back 88 in a normal reclined position, in which it is parallel to its subframe 76 (not shown in Figure 15). Figure 15 also shows, in chain-dotted lines, the seat pan 86 tilted downwards about a horizontal axis adjacent to its rear edge and the seat back 88 in a fully reclined position in which it is pivoted relative to its subframe 76. In neither position does the seat back 88 interfere with the knees of an occupant 90 of the rearward seat 82, 84. Turning to Figure 16, when the seat back 84 is reclined to its normal position, equivalent to the position of the seat back 88 shown in solid lines, the knees of the seated occupant 90 are still clear of the seat back 88 of the seat in front. When the seat pan 82 is tilted and the seat back 84 fully reclined, to positions equivalent to those of the seat pan 86 and the seat back 88 shown in chain-dotted lines, the legs of the seated occupant 90 can fit under the seat pan 86 of the seat in front even when in its tilted position shown in chain-dotted lines. In all of the above embodiments of the invention, conventional manually releasable clutches are provided to hold the various parts of the seats in chosen positions relative to one another. Alternatively the relative positions of the various parts of the seats maybe adjusted using electric, hydraulic or pneumatic motors. Figure 18 shows a sleeper seat having a seat pan 100 and a seat back 102, the latter being illustrated in its reclined position. A fluid chamber 104 has a bottom wall formed by the top surface 106 of the seat pan 100, triangular flexible side walls 108, a bellows-like rear wall 110, and an outer wall 112 which is flexibly connected to the seat pan 100 along its front edge. A duct 114 leads through the seat pan 100 to a reversible pump 116, which serves to pump fluid into and out of the chamber 104. The fluid may be air, in which case the duct end 118 may be open to the atmosphere. Alternatively, it may be connected to a reservoir (not shown). A similar fluid chamber 120 has an inner wall formed by the front surface 122 of the seat back 102, triangular flexible side walls 124 a bellows-like bottom wall 126, and an outer wall 128 which is flexibly connected to the seat pan 100 along its front edge. A pump (not shown), similar to the pump 116, serves to pump fluid into and out of the chamber 120. When the chambers 104 and 120 are filled with fluid, the outer walls 112 and 128 are at a relatively large obtuse angle to one another, as shown in solid lines, significantly reducing the angle between the seat pan 100 and the seat back 102. When substantially all fluid is removed from the chambers 104 and 120, the outer walls 112 and 128 are substantially parallel to the seat pan 100 and the seat back 102 respectively, as shown in chain-dotted lines, and the seat back 102 is ready to be returned to its upright position. Figures 19 to 21 show an alternative fluid-operated sleeper seat having a seat pan 130 and a seat back 132, the latter being illustrated in its reclined position. The top surface of the seat pan 130 has a substantially horizontal rear part 136 and a sloping front part 138 with its front edge lower than its rear edge. The two top surface parts 136 and 138 form the bottom walls of respective fluid chambers 140 and 142, each of which also has triangular flexible side walls 144, 146, bellows-like end wall 148, 150, and outer walls 152, 154 which are flexibly connected to the seat pan 130 along its rear edge and its front edge respectively. Respective ducts 156, 158 lead through the seat pan 100 from each chamber 140, 142 to respective ports of a reversible pump 160, which serves to pump fluid from one of the chambers 140, 142 to the other. The fluid is preferably a liquid so as to be relatively incompressible. Pumping the fluid into the rear chamber 140 tilts the outer walls 152 and 154 to the position shown Figure 20 (and in solid lines in Figure 19). Pumping the fluid into the front chamber 142 tilts the outer walls 152 and 154 to the position shown Figure 21 (and in chain-dotted lines in Figure 19). Two similar chambers 170 and 172 are formed on the front surface of the seat back 132. The outer walls 174, 176 thereof are tilted between the orientation shown in solid lines in Figure 19 and the orientation shown in chain-dotted lines by pumping fluid between the two chambers 170 and 172. The seat illustrated in Figures 19 to 20 may be simplified by replacing the pump 160 with a valve which is preferably spring-biassed into its closed position. When such valve is open, fluid can be displaced out of either of the chambers 140 and 142 and into the other chamber by pressing down on the outer wall 152, 154 of the chamber out of which fluid is to be displaced. The pump (not shown) connected between the chambers 170 and 172 of the seat back 132 may be replaced by a similar valve. In Figures 18 to 20, the outer walls 112, 128, 152, 154, 174, 176 of the fluid chambers are shown as the outer surfaces of the seat. If desired, conventional upholstered cushions may be positioned on top of these outer walls. Although the invention is particularly applicable to aircraft passenger seats, it may also be applied to seats for land, marine and amphibious vehicles.

Claims: A vehicle seat comprising a base frame (10), a seat back (24, 40, 68, 80, 88, 102, 132) mounted on the base frame (10) for angular movement between a substantially upright position and a reclined position, a seat pan (22, 46, 60, 82, 86, 100, 130) having an upper surface, and mounting means supporting the seat pan (22, 46, 60, 100, 130) on the base frame so as to permit change of the orientation of an upper surface of the seat pan (22, 46, 60, 100, 130) between a substantially horizontal position and a tilted position in which its front edge is lower than its rear edge, characterised in that the seat back comprises a first portion (24, 40, 66, 76, 102, 132) which is mounted for angular movement between said substantially upright position and said reclined position, and a second portion (26, 42, 68, 128, 176) having an outer surface supported on mounting means which permit change of its orientation between an erect position in which it is substantially parallel to the first portion and a reclined position in which its lower edge is substantially coplanar with the rear edge of the seat pan (22, 46, 60, 100, 130) when said seat pan is in its tilted position. A vehicle seat according to claim 1, wherein the second portion (26, 42, 68) of the seat back (24, 40, 68) is pivotally mounted for angular movement about a transverse axis (44, 70, 78) between said erect position and said reclined position. A vehicle seat according to claim 1 or 2, wherein the first portion of the seat back comprises an outer portion (24, 40), and the second portion comprises a central portion (26, 42) which is coplanar with the outer portion (24, 40) when in its erect position and has its upper edge behind and below the adjacent part of the outer portion (24, 40) when in its reclined position. A vehicle seat according to claim 1 or 2, wherein the first portion of the seat back comprises an upper portion (24, 40, 72, 132), and the second portion comprises a lower portion (26, 42, 68, 80, 176) which is coplanar with the upper portion when in its erect position and has its upper edge behind and below the lower edge of the upper portion when in its reclined position. A vehicle seat according to any of claims 1 or 2, wherein the first portion of the seat back comprises a substructure (40, 66, 76) located behind the second portion (42, 68) which is mounted on such substructure for pivotal movement about an axis (44, 70, 78) above the bottom of the second portion (42, 68). A vehicle seat according to claim 5, wherein said axis (44, 70, 78) is at substantially equal distances from the top and the bottom of the second portion (42, 68). A vehicle seat according to any preceding claim, wherein the seat pan (46, 82, 86, 100, 130) is mounted for angular movement about a horizontal axis between said normal substantially horizontal position and said tilted position. A vehicle seat according to claim 7, wherein said horizontal axis (48) is at an intermediate position between the front and rear edges of the seat pan (46, 130). A vehicle seat according to claim 7, wherein said horizontal axis is adjacent to the rear edge of the seat pan (22). A vehicle seat according to claim 7, wherein said horizontal axis is adjacent to the front edge of the seat pan (100). A vehicle seat according to claim 1, wherein the front surface (122, 174, 176) of the second portion of the seat back (102, 132) comprises a chamber (120, 170, 172) having flexible side walls (124) of non-uniform height and means for causing displacement of fluid into and out of said chamber (120, 170, 172). A vehicle seat according to claim 11, wherein having two chambers (170, 172) with flexible side walls, one at each end of the seat back (102, 132), together with means for causing displacement of fluid between said chambers (170, 172). A vehicle seat according to claim 1, 11 or 12, wherein the mounting means for the upper surface (106, 152, 154) of the seat pan (100, 130) comprises a chamber (104, 140, 142) having flexible side walls (108, 144, 146) of non-uniform height and means (116, 160) for causing displacement of fluid into and out of said chamber (104, 140, 142). A vehicle seat according to claim 13, having two chambers (140, 142) with flexible side walls (144, 146), one at each end of the seat pan (130) together with means for causing displacement of fluid between said chambers (140, 142).

Inventors: MATSUMIYA JAMES, MATSUMIYA, JAMES AKIRA, MATSUMIYA, JAMES AKIRA, SUNDRIFT
Applicants: BRITAX RUMBOLD LTD, BRITAX RUMBOLD LIMITED
Application year: 1994
Main classification: B60N2
IPC codes: B64D11, B60N2, A47C1